In the construction of poured concrete walls and the like, it is conventional to build scaffolding along the entire wall to allow for finishing of the wall's surface. As the wall progresses upwardly, the scaffolding must follow along in order to allow the finishing work to continue.
One method of raising the top working surface of a scaffold, to follow the construction of the wall, was to erect additional "stories" or "stages" of the scaffold at approximate four to six foot heights. The working surface on top of the scaffold would then be removed and replaced on top of the additional story. The process was typically cumbersome, and the scaffold relied on a series of small diameter posts and cross bracing for strength and rigidity. Unfortunately, the stability of the scaffold decreased as the height increased.
Another method for raising the work surface of a scaffold utilized a scaffold which was attached to a slip-form apparatus, the slip-form being raised continuously by a jack attached to reinforcing rods positioned in the concrete wall being formed. As the slip-form was raised during the pouring of the concrete wall, the scaffold was raised along with the slip-form. However, such apparatus relies on the slip-form type of construction, and requires numerous complicated connections with reinforcing rods placed vertically in the wall to be formed. Such a system is not capable of use on walls which do not use a plurality of vertical reinforcing rods in the wall. Furthermore, such a system requires connection to the wall construction as it is being formed, and does not allow movement independent of the wall construction.
It is therefore a general object of the present invention to provide an improved scaffold jack.
Another object of the present invention is to provide a scaffold jack which is self-supporting away from the wall construction which it serves.
A further object is to provide a scaffold jack which may be raised by a person on the working surface of the scaffold.
These and other objects will be apparent to those skilled in the art.